Abstract:
A highly reliable semiconductor device is manufactured by giving stable electric characteristics to a transistor in which an oxide semiconductor film is used for a channel. An oxide semiconductor film which can have a first crystal structure by heat treatment and an oxide semiconductor film which can have a second crystal structure by heat treatment are formed so as to be stacked, and then heat treatment is performed; accordingly, crystal growth occurs with the use of an oxide semiconductor film having the second crystal structure as a seed, so that an oxide semiconductor film having the first crystal structure is formed. An oxide semiconductor film formed in this manner is used for an active layer of the transistor.
Abstract:
An object is to provide a transparent conductive film having favorable transparency and conductivity at low cost. Another object is to reduce the resistivity of a transparent conductive film formed using conductive oxynitride including zinc and aluminum. Another object is to provide a transparent conductive film that is formed using conductive oxynitride including zinc and aluminum. When aluminum and nitrogen are made to be included in a transparent conductive film formed using oxide including zinc to form a transparent conductive film that is formed using conductive oxynitride including zinc and aluminum, the transparent conductive film can have reduced resistivity. Heat treatment after the formation of the transparent conductive film that is formed using conductive oxynitride including zinc and aluminum enables reduction in resistivity of the transparent conductive film.
Abstract:
Many of the physical properties of a silicon semiconductor have already been understood, whereas many of the physical properties of an oxide semiconductor have been still unclear. In particular, an adverse effect of an impurity on an oxide semiconductor has been still unclear. In view of the above, a structure is disclosed in which an impurity that influences electrical characteristics of a semiconductor device including an oxide semiconductor layer is prevented or is eliminated. A semiconductor device which includes a gate electrode, an oxide semiconductor layer, and a gate insulating layer provided between the gate electrode and the oxide semiconductor layer and in which the nitrogen concentration in the oxide semiconductor layer is 1×1020 atoms/cm3 or less is provided.
Abstract:
In the transistor including an oxide semiconductor film, which includes a film for capturing hydrogen from the oxide semiconductor film (a hydrogen capture film) and a film for diffusing hydrogen (a hydrogen permeable film), hydrogen is transferred from the oxide semiconductor film to the hydrogen capture film through the hydrogen permeable film by heat treatment. Specifically, a base film or a protective film of the transistor including an oxide semiconductor film has a stacked-layer structure of the hydrogen capture film and the hydrogen permeable film. At this time, the hydrogen permeable film is formed on a side which is in contact with the oxide semiconductor film. After that, hydrogen released from the oxide semiconductor film is transferred to the hydrogen capture film through the hydrogen permeable film by the heat treatment.
Abstract:
A minute transistor is provided that includes a first insulator, a second insulator, a first, conductor, a second conductor, and third conductor, in which an angle is formed between a side surface of the first insulator and a top surface of the first conductor, and a length between the first conductor and a surface of the second conductor closest to the first conductor is at least greater than a length between the first conductor and the third conductor.
Abstract:
There have been cases where transistors formed using oxide semiconductors are inferior in reliability to transistors formed using amorphous silicon. Thus, in the present invention, a semiconductor device including a highly reliable transistor formed using an oxide semiconductor is manufactured. An oxide semiconductor film is deposited by a sputtering method, using a sputtering target including an oxide semiconductor having crystallinity, and in which the direction of the c-axis of a crystal is parallel to a normal vector of the top surface of the oxide semiconductor. The target is formed by mixing raw materials so that its composition ratio can obtain a crystal structure.
Abstract:
Many of the physical properties of a silicon semiconductor have already been understood, whereas many of the physical properties of an oxide semiconductor have been still unclear. In particular, an adverse effect of an impurity on an oxide semiconductor has been still unclear. In view of the above, a structure is disclosed in which an impurity that influences electrical characteristics of a semiconductor device including an oxide semiconductor layer is prevented or is eliminated. A semiconductor device which includes a gate electrode, an oxide semiconductor layer, and a gate insulating layer provided between the gate electrode and the oxide semiconductor layer and in which the nitrogen concentration in the oxide semiconductor layer is 1×1020 atoms/cm3 or less is provided.
Abstract:
Many of the physical properties of a silicon semiconductor have already been understood, whereas many of the physical properties of an oxide semiconductor have been still unclear. In particular, an adverse effect of an impurity on an oxide semiconductor has been still unclear. In view of the above, a structure is disclosed in which an impurity that influences electrical characteristics of a semiconductor device including an oxide semiconductor layer is prevented or is eliminated. A semiconductor device which includes a gate electrode, an oxide semiconductor layer, and a gate insulating layer provided between the gate electrode and the oxide semiconductor layer and in which the nitrogen concentration in the oxide semiconductor layer is 1×1020 atoms/cm3 or less is provided.
Abstract:
In a manufacturing process of a transistor including an oxide semiconductor film, oxygen doping treatment is performed on the oxide semiconductor film, and then heat treatment is performed on the oxide semiconductor film and an aluminum oxide film provided over the oxide semiconductor film. Consequently, an oxide semiconductor film which includes a region containing more oxygen than a stoichiometric composition is formed. The transistor formed using the oxide semiconductor film can have high reliability because the amount of change in the threshold voltage of the transistor by a bias-temperature stress test (BT test) is reduced.
Abstract:
In a manufacturing process of a transistor including an oxide semiconductor film, oxygen doping treatment is performed on the oxide semiconductor film, and then heat treatment is performed on the oxide semiconductor film and an aluminum oxide film provided over the oxide semiconductor film. Consequently, an oxide semiconductor film which includes a region containing more oxygen than a stoichiometric composition is formed. The transistor formed using the oxide semiconductor film can have high reliability because the amount of change in the threshold voltage of the transistor by a bias-temperature stress test (BT test) is reduced.